Strategic Effects of Incomplete and Renegotiation-Proof Contracts

It is well known that non-renegotiable contracts with third parties may have an effect on the outcome of a strategic interaction and thus serve as a commitment device. We address this issue when contracts are renegotiable. More precisely, we analyze the equilibrium outcomes of twostage games with renegotiation-proof third-party contracts in relation to the equilibrium outcomes of the same game without contracts. We assume that one of the parties in the contractual relationship is unable to observe everything that happens in the game when played by the other party. This implies that contracts are incomplete and we show that such incompleteness restricts the set of equilibrium outcomes to a subset of Nash equilibrium outcomes of the game without contracts. Introducing renegotiation, in general, imposes further constraints and in some games implies that only subgame perfect equilibrium outcomes can be supported. However, there is a large class of games in which non-subgame perfect equilibriumoutcomes can also be supported, and hence, third-party contracts still have strategic implications even when they are renegotiable.Third-Party Contracts, Strategic Delegation, Incomplete Contracts, Renegotiation

Delegation with Incomplete and Renegotiable Contracts

It is well known that delegating the play of a game to an agent via incentive contractsmay serveas a commitment device and hence provide a strategic advantage. Previous literature has shown that any Nash equilibrium outcome of an extensive-form principals-only game can be supported as a sequential equilibrium outcome of the induced delegation game when contracts are unobservable and non-renegotiable. In this paper we characterize equilibriumoutcomes of delegation games with unobservable and incomplete contractswith andwithout renegotiation opportunities under the assumption that the principal cannot observe every history in the game when played by her agent. We show that incompleteness of the contracts restricts the set of outcomes to a subset of Nash equilibrium outcomes and renegotiation imposes further constraints. Yet, there is a large class of games in which non-subgame perfect equilibrium outcomes of the principals-only game can be supported even with renegotiable contracts, and hence delegation still has a bite.Strategic Delegation, Incomplete Contracts, Renegotiation.

Games with Externalities and Delegation to a Common Agent

I present a model in which the players of a game have the option to delegate parts of their strategies to a third party who has an interest in the outcome of the game. I analyze whether the game with delegation to a common agent improves over the equilibrium of the original game. This paper contributes to the literature on private common agency and to the failure of the revelation principle with multiple principals. One contribution of this paper is the characterization of the complete set of equilibrium outcomes for the game with delegation, including the asymmetric outcomes. I also provide an answer to the question whether the results of the existing models of private common agency are robust to mixed strategy deviations and shed light on the persistence of the failure of revelation principle.Common Agency Games, Delegation, Revelation Principle, Games with Externalities.